1. Field of the Invention
This invention relates to a wire harness fixing structure in an instrument panel and also to an instrument panel. More specifically, the invention relates to a wire harness fixing structure in which a harness fixing portion, which enables the discharge of water, for example, resulting from dew condensation developing in a harness installation passage, is formed in the harness installation passage so as to fix a wire harness. The invention also relates to an instrument panel having such a fixing structure.
2. Related Art
FIG. 10 shows an instrument panel of a vehicle, such as an automobile, disclosed in Japanese Patent unexamined Publication No. 5-77659.
This instrument panel 1 comprises an upper instrument panel member 2 and a lower instrument panel member 3 both of which are made of a synthetic resin. A meter hood 4 is adapted to be mounted on the upper instrument panel member 2.
Air outlet ports 5 for defrosting purposes are formed in a front end portion of the upper instrument panel member 2, and air outlet ports 6 and 7 for air-conditioning purposes are formed respectively in opposite (right and left) side portions (with respect to the passenger room of the vehicle) and, a central portion of the upper instrument panel member 2. Covers 6a and 7a, each having an air blowout condition adjusting function (such as the direction and amount of the air), are provided respectively in the air outlet ports 6 and 7.
The upper instrument panel member 2 has a tray 8 for holding small articles. The meter hood 4 is adapted to be mounted on a mounting portion 9 formed at the upper instrument panel member 2, and meters (not shown), including a speedometer and a tachometer, are provided within this meter hood.
In FIGS. 10 and 11, an air duct 10 for air-conditioning purposes, an air duct 11 for defrosting purposes, and a harness installation passage 12 for receiving circuit members mounted on the instrument panel 1 (see FIG. 10) are formed in a parting engagement surface of the lower instrument panel member 3 for engagement with the upper instrument panel member 2 (see FIG. 10). Each of the air ducts 10 and 11 and the harness installation passage 12 has a channel-shaped cross-section. An air introducing port 13 for introducing the air from an air-conditioning unit (not shown) is formed at the air duct 10. Similarly, an air introducing port 14 is formed in the air duct 11.
In the example shown in FIG. 10, electrically-conductive stripes, corresponding to a wire harness, are coated or printed directly on the harness installation passage 12.
As shown in FIG. 12, air ducts 16 and 17 and a harness installation passage 18, corresponding respectively to the air ducts 10 and 11 (see FIG. 11) and the harness installation passage 12 (see FIG. 11), are formed in a parting engagement surface of the upper instrument panel member 2 for engagement with the lower instrument panel member 3. When the upper and lower instrument panel members 2 and 3 are engaged with each other, the various ducts and the passage are formed. In the above conventional technique, the instrument panel 1 has a two-piece construction, that is, the upper instrument panel member 2 and the lower instrument panel member 3, as shown in FIG. 10. Therefore, the air ducts 10 (16) and 11 (17) and the harness installation passage 12 (18) can be formed integrally in the instrument panel member by molding. Also, with respect to the air ducts 10 (16) and 11 (17) for example , a connection tube or a bellows tube for the air duct is not required. Thus the assembling process is simplified.
On the other hand, the harness installation passages 12 and 18 are formed along the air ducts 10 and 16, respectively, as shown in FIG. 13. Therefore, even if care is taken so as to prevent the air from leaking from the air ducts 10 and 16 through a portion indicated by arrow P, there is a possibility that dew condensation will develop on the inner surfaces of the harness installation passages 12 and 18 because of a change of the ambient temperature (to which the instrument panel 1 is subjected) and the temperature difference between the air ducts 10 and 16 and the harness installation passages 12 and 18.
Water, resulting from this condensation, will collect in the harness installation passages 12 and 18, which is undesirable from the electrical point of view.
The electrically-conductive stripes 15 are provided in the harness installation passage 12 (18) as shown in FIG. 10. However, in the case where a wire harness 19 is installed as shown in FIG. 13, this wire harness 19 needs to be fixed so that it will not be dislodged. More specifically, in order to suppress the shaking of the wire harness 19 due to vibrations developing during the travel of the vehicle, the wire harness 19 must be fixed by bonding it directly to the instrument panel member or by using protectors or clips (not shown) attached in advance to the wire harness 19.
Therefore, the number of the component parts increases, so that the mounting operation is complicated.
Further, in the case of using the above protectors or the clips (not shown), a certain degree of dimensional accuracy is required when manufacturing the wire harness 19 so that the protectors or the clips can be mounted respectively on predetermined portions of the wire harness. Therefore, the mounting operation is further complicated, and this affects the productivity.